1. Field of the General Inventive Concept
Apparatuses and methods consistent with exemplary embodiments relate to a customer replaceable unit monitoring (CRUM) chip, an image forming apparatus, and a communication method of the CRUM chip, and more particularly, to a CRUM chip, an image forming apparatus, and a communication method of a CRUM chip which monitor presence/absence of integrity using integrity monitoring data in a communication process.
2. Description of the Related Art
With the spread activation of computers, the spread of computer peripherals is increasing day by day. Examples of computer peripherals include image forming apparatuses such as printers, facsimile, scanners, copiers, and multifunction peripherals.
Image forming apparatuses use ink or toner to print images on paper. When an image forming process is performed, ink and toner is used. Thus the ink or toner is exhausted when the ink or toner is used over a predetermined time. In this case, a unit which stores ink or toner should be newly replaced. Parts or components which are replaceable during use of the image forming apparatus are referred to as consumables units or replaceable units. Here, for clarity, the parts or components referred to as consumables units.
Consumables units include units which are replaced when a property is changed due to use of a consumable over a fixed period and good print quality is not expected, in addition to the units which are replaced due to exhaustion of ink or toner. That is, in addition to developers for colors, there are parts such as an intermediate transfer belt that are consumables units.
Specifically, a charging unit, a transfer unit, a fusing unit, and the like are used in laser image forming apparatuses. When various kinds of rollers, belts, and the like used in each unit are used over a lifetime limit, the roller and belts may be worn and spoiled. Thus, image quality is considerably degraded. To allow a printing job for clean images to be performed, users should replace component units, that is, consumables units at appropriate replacement times.
In recent years, consumables units have been implemented to be provided with a memory therein and to transmit and receive data from a main body of an image forming apparatus so that the consumables unit is appropriately managed.
That is, various use information such as a number of printing sheets, a number of output dots, and a term of use of the image forming apparatus is recorded in the consumables unit itself so that it is possible to accurately manage a replacement time of the consumables unit, and the like.
A main controller provided in a main body of the image forming apparatus performs communication with a memory unit provided in the consumables unit to manage the information. However, various variables are present in the communication process. For example, there may be noise interference caused by an electronic circuit or a motor provided in the image forming apparatus or attack by a hacker who controls the main controller or the memory unit for malicious purposes.
Communication data may be changed due to the variables. For example, when a corresponding job is completed, the consumables unit transmits information such as the number of printing sheets, the number of output dots, and a remaining amount of toner to the main controller and copies the information into a nonvolatile memory of the main controller. In this case, when data is read as a wrong value such as 0xFFFFFFFF, there is the risk in which the main controller recognizes that a corresponding consumables unit's life has ended. Meanwhile, the hacker may reset use information of the consumables unit whose life has ended as zero (0) and set the consumables unit to be in a reproducible state. Therefore, the consumables unit whose life has ended is misrepresented as containing ink or toner and is used so that failure of the image forming apparatus or degradation of image quality is caused.
Therefore, there is a need for technology to effectively monitor a communication error between the consumables unit and the image forming apparatus and promoting stability of data.